MongoDB

UpdateHow to keep the operation:$set: ChangeDb.t.update ({uname: "BB"},{$set: {addr: "BJ"}})$inc: Increase or decreaseDb.t.update ({"uname": "HY"},{$inc: {"Sal": [], $set: {"addr": "Gaozhou"}})Change and increaseDb.t.update ({"uname": "BB"},{$inc: {"

Master node (primary) with slave node (secondary) and quorum node (arbiter)A three-member replica set with two members that store data has:a master node.One from the node. The slave node can become the primary node in the election.A quorum node

Http://www.cnblogs.com/best/p/6212807.htmlOpen the MongoDB installation directory such as "C:\Program Files\mongodb\server\3.4\bin" and create a new Mongo.config file in this directory with the following file contents:# #数据库目录 # #dbpath =c:\data\db#

Index:Db.media.createIndex ({"Tracklist": 1}) 1 means ascending -1 = Descending Let's focus on the case where the array is indexed.Build a collection: Db.media.insertOne ({"Type": "CD", "Artist": "Nirvana", "title": "Nevermind",

Using DbrefsThere are three fields in Dbrefs- $ref-This field specifies the collection of referenced documents $id-This field specifies the field that references the document _id $db-This is an optional field and contains the name

This blog is written after listening to the lesson-Getting started with MongoDBWhen the amount of data is small, it can be queried quickly without using an index, but when the amount of data is large, the index is used to improve

Aggregation Pipeline:Common operators introduce:$project: Include, exclude, rename, and display fields$match: query, need the same parameters as find ()$limit: Limit the number of results$skip: Ignore the number of results$sort: Sort results by a

MongoDB add replica and modify priority1. Add replica set#在primary节点上执行>rs.add ({host: "192.168.1.11:27017", priority:0})#host: Specify the IP and port of the MongoDB server to be added#priority: Specify permissions for the replica set2. Adding the

Create the file mg.conf in the bin directory sibling directory and write the following:Dbpath=d:\program Files\mongodb\server\3.2\data #数据库路径Logpath=d:\program Files\mongodb\server\3.2\logs\mongo.log #日志输出文件路径Logappend=true #错误日志采用追加模式Journal=true

Detailed illustrations documenting the process of installing the MONGO database in Win7 64. The installed version is mongodb-win32-x86_64-2008plus-ssl-3.4.1-signed.Sample version: Mongodb-win32-x86_64-2008plus-ssl-3.4.1-signedSystem: Win 7 bit 8g

1. Download the MongoDB installation package on the official website, I downloaded the 3.4.6 system for win10_642. Need to install vc++2015 the Win7 system is not installed during installation. Win10 installed in the last resort3. Install MongoDB

1.SBT Content:Name: = "Data_ana"Version: = "1.0"scalaversion: = "2.11.8"librarydependencies ++= Seq ("Org.apache.spark" percent "Spark-core"% "2.2.0","Org.apache.spark" percent "spark-sql"% "2.2.0","Org.apache.hadoop"% "hadoop-client"%

1 Creating an Index1 is a positive-order index, and 1 is a negative-order indexIndexing increases query time by pressing, reducing insertion timeDb.books.ensureIndex ({number:1})2. Create an index, specify a nameDb.book.ensureIndex ({name:-1},{name:

Mongdb is a non-relational distributed storage database based on C + +, which describes how MongoDB is started:1. If you shut down normally during the last use, you can double-click the Mongod.exe in the bin directory to enable the MongoDB server

start cmd with AdministratorEnter the installation directory               input: Mongod--auth--port 3406--dbpath= Library address--logpath= full address--install--servicename "Custom Name"Note:The library address can be specified only to the folder,

Just started to learn MongoDB, made a collation of notes. is based on Nodejs to learn.1.mongodb IntroductionMongoDB is written in the C + + language and is an open source database system based on distributed file storage. In the case of high load,

This article mainly introduces MongoDB database additions and deletions to check operation.IncreaseMongoDB, like other relational databases, uses insert to add data to the collection.db.collectionName.insert(内容)Show all collections in the

1. Common commands show DBS Show all databases use dbname into dbname database, if not present, db View database show collections displays the collection in the database--equivalent to the table in MySQL!

In the past four blogs, we attached importance to the index, including description and comparison with usage of index. Now in this blog, we'll mainly focus on the basic operation of index. Such query, remove, repair and so on.1. View IndexGetindexes

1. Download the installation packageCurl-o https://fastdl.mongodb.org/linux/mongodb-linux-x86_64-3.0.6.tgzCurl-o https://fastdl.mongodb.org/linux/mongodb-linux-x86_64-amazon-3.4.5.tgz2. Unzip the installation packageTAR-ZXVF mongodb-linux-x86_64-3.0.